TW202005455A - PRACH structure in NR unlicensed - Google Patents

Abstract

A wireless transmit/receive unit (WTRU) performing PRACH may adjust a PRACH format based on a different numerology of a channel that the WTRU attempts to access. The PRACH format may be characterized by an upsampling ratio and a sequence length. The WTRU may determine numerology of a channel that the WTRU attempts to access including a subcarrier spacing of the channel. The WTRU may determine a PRACH format based on the determined numerology. The sequence length may be fixed, and the upsampling ratio may vary based on the subcarrier spacing. The upsampling ratio may indicate a set of subcarriers used for a PRACH sequence within a PRACH bandwidth. The WTRU may perform random access using the determined PRACH format.

Description

Unauthorized PRACH structure in NR

Cross-reference of related applications

This application claims the benefits of US provisional patent application 62/652,647 filed on April 4, 2018 and US provisional patent application 62/669,091 filed on May 9, 2018, the contents of which are incorporated herein by reference.

Mobile communication using wireless communication continues to develop. The fifth generation can be called 5G. The previous (traditional) generation mobile communication may be, for example, the fourth generation (4G) long-term evolution (LTE).

This document discloses the implementation (eg, system, method, and/or device) of a physical random access channel (PRACH) structure. These implementations can be implemented in 3GPP, for example in New Radio (NR). The implementation may include the phase alignment portion of the PRACH sequence. Implementation may include Golay construction for PRACH sequences. Physical channel shared channel (PUSCH) puncturing for interference mitigation of adjacent channels can be performed. A common backoff counter for multiple wireless transmission/reception units (WTRUs) may be implemented. The implementation may include (eg, one) interleaved PRACH within the cluster. LBT can be implemented in narrow-band PRACH.

The wireless transmission/reception unit (WTRU) performing PRACH may adjust the PRACH format based on different parameter configurations (numerology) of the channel that the WTRU is trying to access. The PRACH format can be characterized by upsampling rate and sequence length. The WTRU may determine the parameter configuration of the channel that the WTRU attempts to access, including the subcarrier spacing of the channel. The WTRU may determine the PRACH format based on the determined parameter configuration. The sequence length may be fixed, and the upsampling rate may vary based on the subcarrier spacing. For example, if the physical random access channel has a first subcarrier spacing, the first upsampling rate may be used. If the physical random access channel has a second subcarrier spacing smaller than the first subcarrier spacing, a second upsampling rate greater than the first upsampling rate may be used to keep the sequence length at a fixed value. The upsampling rate may indicate the group of subcarriers used for the PRACH sequence within the PRACH bandwidth. For example, if the upsampling rate is 1, the subcarrier group may be continuous, and if the upsampling rate is 2, the subcarrier group may include alternative subcarriers. The WTRU may use the determined PRACH format to perform random access.

A wireless transmission/reception unit (WTRU) that performs PRACH can adjust the PRACH format based on whether the previous attempt to access the channel was successful. The WTRU may determine whether the previous attempt to access the channel was successful based on the received indication. If the previous attempt is unsuccessful, the WTRU may determine a second PRACH format that includes an upsampling rate that is different from the first upsampling rate of the first PRACH format used in the previous attempt to access the channel.

FIG. 1A is a diagram illustrating an exemplary communication system 100 that can implement one or more disclosed embodiments. The communication system 100 may be a multiple access system that provides content to multiple wireless users, such as voice, data, video, messaging, broadcast, and so on. The communication system 100 can enable multiple wireless users to access such content by sharing system resources (including wireless bandwidth). For example, the communication system 100 may use one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), Single carrier FDMA (SC-FDMA), zero-tail unique word DFT extended OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtering OFDM, filter bank multi-carrier (FBMC), etc.

As shown in FIG. 1A, the communication system 100 may include wireless transmission/reception units (WTRUs) 102a, 102b, 102c, 102d, RAN 104/113, CN 106/115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it is understood that the disclosed embodiments take into account any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. As an example, WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as "base station" and/or "STA") may be configured to transmit and/or receive wireless signals, and may include: user equipment (UE), mobile station, fixed or mobile subscriber unit, subscription-based unit, pager, mobile phone, personal digital assistant (PDA), smartphone, laptop, small notebook, personal computer, wireless sensor , Hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMD), vehicles, drones, medical devices and applications (eg, remote surgery), industrial devices and applications (For example, robots and/or other wireless devices operating in industrial and/or automatic processing chain environments), consumer electronics devices, devices operating on commercial and/or industrial wireless networks, etc. Any one of WTRUs 102a, 102b, 102c, 102d may be referred to as a UE interchangeably.

The communication system 100 may also include a base station 114a and/or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to have a wireless interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, for example , CN 106/115, Internet 110, and/or other networks 112. As an example, the base stations 114a and 114b may be base station transceiver stations (BTS), Node B, eNode B, Home Node B, Home eNode B, gNB, NR Node B, Site Controller, and Access Point (AP ), wireless routers, etc. Although the base stations 114a, 114b are each depicted as a single element, it should be understood that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller ( RNC), repeater. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies that may be referred to as cells (not shown). These frequencies can be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. Cells may provide wireless service coverage for a specific geographic area, which may be relatively fixed or may change over time. Cells can be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, that is, one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology, and may use multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and/or receive signals in a desired spatial direction.

The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via an air interface 116, which may be any suitable wireless communication link (eg, radio frequency (RF), microwave, , Centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 can be established using any suitable radio access technology (RAT).

More specifically, as described above, the communication system 100 may be a multiple access system, and one or more channel access methods, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc., may be used. For example, base station 114a and WTRUs 102a, 102b, 102c in RAN 104/113 may implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to Establish air interface 115/116/117. WCDMA may include communication protocols such as High Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include high-speed downlink (DL) packet access (HSDPA) and/or high-speed UL packet access (HSUPA).

In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may use Long Term Evolution (LTE) and LTE-Advanced (LTE- A) and/or Advanced LTE Pro (LTE-A Pro) to establish the air interface 116.

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as NR radio access, which may use a new radio (NR) to establish the air interface 116.

In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using the dual connection (DC) principle. Therefore, the air interface used by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions to/from multiple types of base stations (eg, eNB and gNB).

In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies, such as IEEE 802.11 (ie, wireless fidelity (WiFi), IEEE 802.16 (ie, Global Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA 2000 1X, CDMA2000 EV-DO, interim standard 2000 (IS-2000), interim standard 95 (IS-95), interim standard 856 (IS-856), global mobile communications system (GSM), for GSM evolution Enhanced data rate (EDGE), GSMEDGE (GERAN), etc.

For example, the base station 114b in FIG. 1A may be a wireless router, a home Node B, a home eNode B, or an access point, and any suitable RAT may be used to facilitate wireless connectivity in local areas, such as commercial premises, residential, Vehicles, campuses, industrial facilities, air corridors (for example, for drones), roads, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize cellular-based RATs (eg, WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish pico cells or Femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not be required to access the Internet 110 via the CN 106/115.

RAN 104/113 may communicate with CN 106/115, which may be configured to provide voice, data, applications, and/or Internet protocols to one or more of WTRUs 102a, 102b, 102c, 102d Any type of network for voice (VoIP) services. Data can have different quality of service (QoS) requirements, such as different liquidity requirements, latent time requirements, fault tolerance requirements, reliability requirements, data flow requirements, and mobility requirements. CN 106/115 can provide call control, billing services, mobile location-based services, prepaid calling, Internet connection, video distribution, etc., and/or perform advanced security functions, such as user authentication. Although not shown in FIG. 1A, it should be understood that RAN 104/113 and/or CN 106/115 may communicate directly or indirectly with other RANs that use the same RAT or a different RAT as RAN 104/113. For example, in addition to being connected to RAN 104/113 that can utilize NR radio technology, CN 106/115 can also be connected to another RAN (not shown) using GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology. ) Communication.

CN 106/115 may also be used as a gateway for WTRUs 102a, 102b, 102c, 102d to access PSTN 108, Internet 110, and/or other networks 112. PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a system of globally interconnected computer networks and devices that use common communication protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) in the TCP/IP Internet Protocol family And/or Internet Protocol (IP). The network 112 may include wired and/or wireless communication networks owned and/or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may use the same RAT or a different RAT as the RAN 104/113.

Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple devices for communicating with different wireless networks through different wireless links Transceivers). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may employ cellular-based radio technology, and to communicate with a base station 114b that may employ IEEE 802 radio technology.

FIG. 1B is a system diagram illustrating an exemplary WTRU 102. As shown in FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmission/reception element 122, a speaker/microphone 124, a keypad 126, a display/trackpad 128, a non-removable memory 130, a removable Memory 132, power supply 134, global positioning system (GPS) chipset 136 and/or other peripheral devices 138, etc. It should be understood that WTRU 102 may include any sub-combination of the aforementioned elements while remaining consistent with the implementation.

The processor 118 may be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with the DSP core, a controller, and a micro-controller Device, application specific integrated circuit (ASIC), field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), state machine, etc. The processor 118 may perform signal encoding, data processing, power control, input/output processing, and/or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, and the transceiver 120 may be coupled to the transmission/reception element 122. Although FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it should be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

The transmission/reception element 122 may be configured to transmit signals to or receive signals from the base station (eg, the base station 114a) via the air interface 116. For example, in one embodiment, the transmission/reception element 122 may be an antenna configured to transmit and/or receive RF signals. In one embodiment, the transmission/reception element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmission/reception element 122 may be configured to transmit and/or receive RF and optical signals. It should be understood that the transmission/reception element 122 may be configured to transmit and/or receive any combination of wireless signals.

Although the transmission/reception element 122 is depicted as a single element in FIG. 1B, the WTRU 102 may include any number of transmission/reception elements 122. More specifically, WTRU 102 may employ MIMO technology. Therefore, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (eg, multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

The transceiver 120 may be configured to modulate the signal to be transmitted by the transmission/reception element 122 and demodulate the signal received by the transmission/reception element 122. As described above, WTRU 102 may have multi-mode capabilities. Accordingly, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

The processor 118 of the WTRU 102 may be coupled to the speaker/microphone 124, the keypad 126, and/or the display/trackpad 128 (eg, a liquid crystal display (LCD) display unit, or an organic light emitting diode (OLED) display unit), and may User input data is received from the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (eg, a liquid crystal display (LCD) display unit, or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, keypad 126, and/or display/trackpad 128. In addition, the processor 118 can access information from any type of suitable memory and store data in the memory, such as non-removable memory 130 and/or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read only memory (ROM), a hard disk, or any other type of storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and so on. In other embodiments, the processor 118 may access information from memory that is not physically located on the WTRU 102 (eg, a server or a home computer (not shown)), and store data in the memory.

The processor 118 may receive power from the power supply 134 and may be configured to distribute and/or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. As an example, the power supply 134 may include one or more dry batteries (eg, nickel cadmium (NiCd) batteries, nickel zinc (NiZn) batteries, nickel metal hydride (NiMH) batteries, lithium ion (Li-ion) batteries, etc.), solar energy Batteries, fuel cells, etc.

The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide position information (eg, longitude and latitude) regarding the current location of the WTRU 102. The WTRU 102 may receive location information in addition to or in place of the GPS chipset 136 from base stations (eg, base stations 114a, 114b) via the air interface 116 and/or based on received from two or more nearby base stations The timing of the signal determines its position. It should be understood that WTRU 102 may obtain location information by any suitable location determination method, while remaining consistent with the implementation.

The processor 118 may further be coupled to other peripheral devices 138, which may include one or more software and/or hardware modules that provide additional features, functions, and/or wired or wireless connections. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos or video), universal serial bus (USB) ports, vibration devices, TV transceivers, hands-free headsets, Bluetooth® Modules, FM radio units, digital music players, media players, video game player modules, Internet browsers, virtual reality and/or augmented reality (VR/AR) devices, activity tracking器等。 Device. The peripheral device 138 may include one or more sensors, and the sensors may be gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time One of a sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor or Multiple.

The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (eg, for uplink (eg, for transmission) and downlink (eg, for reception) Special subframes are associated) can be parallel and/or simultaneous. A full-duplex radio may include an interference management unit to perform signal processing by hardware (for example, a choke coil), or by a processor (for example, a separate processor (not shown) or by the processor 118) Reduce and/or substantially eliminate self-interference. In one embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (eg, for uplink (eg, for transmission) or down-link (eg , Used to receive) the special sub-frames associated with).

FIG. 1C is a system diagram showing the RAN 104 and the CN 106 according to the embodiment. As described above, RAN 104 may use E-UTRA radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. The RAN 104 can also communicate with the CN 106.

The RAN 104 may include eNodeBs 160a, 160b, 160c, but it should be understood that the RAN 104 may include any number of eNodeBs, while remaining consistent with the implementation. The eNodeB 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the eNodeB 160a, 160b, 160c may implement MIMO technology. Thus, eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and/or receive wireless signals from WTRU 102a.

Each of the eNodeB 160a, 160b, 160c may be associated with a special cell (not shown), and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and/or DL Cheng et al. As shown in FIG. 1C, eNodeBs 160a, 160b, and 160c can communicate with each other through the X2 interface.

The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a service gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is depicted as part of CN 106, it should be understood that any of these elements may be owned and/or operated by an entity other than the CN operator.

The MME 162 can be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via the S1 interface, and can be used as a control node. For example, MME 162 may be responsible for verifying users of WTRUs 102a, 102b, 102c, bearer activation/deactivation, selection of special service gateways during initial attachment of WTRUs 102a, 102b, 102c, and so on. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) employing other radio technologies (eg, GSM and/or WCDMA).

The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to or from the WTRUs 102a, 102b, 102c, and forward and forward user data packets. SGW 164 may perform other functions, such as anchoring the user plane during the handover between eNodeBs, triggering paging when DL data is available to WTRUs 102a, 102b, 102c, managing and storing the context of WTRUs 102a, 102b, 102c, and so on.

SGW 164 may be connected to PGW 166, which may provide WTRUs 102a, 102b, 102c with access to packet-switched networks (eg, Internet 110) to facilitate WTRUs 102a, 102b, 102c and IP-enabled devices Communication.

CN 106 can facilitate communication with other networks. For example, CN 106 may provide WTRUs 102a, 102b, 102c with access to circuit-switched networks (eg, PSTN 108) to facilitate communications between WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, CN 106 may include an IP gateway (eg, an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 106 and PSTN 108, or may communicate with the gateway. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and/or wireless networks owned and/or operated by other service providers.

Although the WTRU is described as a wireless terminal in FIGS. 1A to 1D, in certain representative embodiments, it is expected that such a terminal may use a wired interface (eg, temporary or permanent) with a communication network.

In a representative embodiment, the other network 112 may be a WLAN.

A WLAN in an infrastructure basic service set (BSS) mode may have an access point (AP) for BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interface to a distribution system (DS) or other type of wired/wireless network that sends traffic into and/or out of the BSS. Traffic from outside the BSS to the STA can be reached by the AP and can be delivered to the STA. Traffic originating from the STA to a destination outside the BSS can be transmitted to the AP to be delivered to the respective destination. Traffic between STAs within the BSS can be transmitted by the AP, for example, the source STA can transmit traffic to the AP, and the AP can pass the traffic to the destination STA. The traffic between STAs in the BSS can be considered and/or referred to as point-to-point traffic. Direct link establishment (DLS) can be used to transmit point-to-point traffic between the source and destination STAs (eg, directly between them). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (for example, all STAs) within IBSS or using IBSS may directly communicate with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode. "

When using the 802.11ac infrastructure operating mode or similar operating mode, the AP can transmit beacons on a fixed channel (such as the main channel). The main channel can be a fixed width (for example, 20 MHz wide bandwidth) or a width dynamically set by communication. The main channel may be the operation channel of the BSS, and may be used by the STA to establish a connection with the AP. In some representative embodiments, carrier sense multiple access (CSMA/CA) with collision avoidance may be implemented, for example, in 802.11 systems. For CSMA/CA, the STA (for example, each STA) (including AP) can sense the main channel. If the main channel is sensed/detected by the special STA and/or determined to be busy, then the special STA may back off. One STA (eg, only one station) can transmit at any given time in a given BSS.

High-throughput (HT) STAs can communicate using 40 MHz wide channels, for example, by combining a main 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

VHT STA can support 20 MHz, 40 MHz, 80 MHz and/or 160 MHz wide channels. The 40 MHz and/or 80 MHz channels can be formed by combining consecutive 20 MHz channels. The 160 MHz channel can be formed by combining 8 consecutive 20 MHz channels, or by combining two non-contiguous 80 MHz channels. This can be referred to as the 80+80 configuration. For the 80+80 configuration, after channel encoding, the data can be separated by a segment parser that can split the data into two streams. Inverse fast Fourier transform (IFFT) processing and time domain processing can be performed separately for each stream. The stream can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver receiving the STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be transmitted to the media access control (MAC).

802.11af and 802.11ah support sub-1GHz operation mode. Compared with the ones used in 802.11n and 802.11ac, the channel operation bandwidth and carrier in 802.11af and 802.11ah are reduced. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths that use non-TVWS spectrum. According to a representative embodiment, 802.11ah can support meter type control/machine type communication, such as MTC devices in a macro coverage area. The MTC device may have certain capabilities, such as limited capabilities, including support (eg, support only) of certain and/or limited bandwidth. The MTC device may include a battery with a battery life above a critical value (eg, to maintain a very long battery life).

WLAN systems that can support multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah include channels that can be designated as main channels. The bandwidth of the main channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the main channel can be set and/or limited by the STA (from all STAs operating in the BSS), which supports the minimum bandwidth operation mode. In the 802.11ah example, for STAs that support (eg, only support) 1 MHz mode (eg, MTC type devices), the main channel can be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz , 8 MHz, 16 MHz and/or other channel bandwidth operation modes. Carrier sense and/or network allocation vector (NAV) settings may depend on the state of the main channel. If the main channel is busy, for example, because the STA (only supports 1 MHz operation mode) is transmitting to the AP, even if most of the frequency bands remain idle and may be available, the entire available frequency band may be considered busy.

In the United States, the available frequency band that can be used by 802.11ah is 902 MHz to 928 MHz. In South Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands range from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz, depending on the country code.

FIG. 1D is a system diagram showing RAN 113 and CN 115 according to an embodiment. As mentioned above, RAN 113 may use NR radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 113 can also communicate with CN 115.

The RAN 113 may include gNBs 180a, 180b, 180c, but it should be understood that the RAN 113 may include any number of gNBs, while remaining consistent with the implementation. Each of gNB 180a, 180b, 180c may include one or more transceivers for communicating with WTRUs 102a, 102b, 102c via an air interface 116. In one embodiment, gNB 180a, 180b, 180c may implement MIMO technology. For example, gNB 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from gNB 180a, 180b, 180c. Thus, for example, gNB 180a may use multiple antennas to transmit wireless signals to and/or receive wireless signals from WTRU 102a. In one embodiment, gNB 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers can be on the unlicensed spectrum, while the remaining component carriers can be on the licensed spectrum. In one embodiment, gNB 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a, 180b, 180c (and/or gNB 180c).

WTRUs 102a, 102b, 102c may communicate with gNB 180a, 180b, 180c using transmissions associated with scalable parameter configurations. For example, OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different parts of the wireless transmission spectrum. WTRUs 102a, 102b, and 102c can use various or scalable length subframes or transmission time intervals (TTIs) to communicate with gNB 180a, 180b, and 180c (eg, include different numbers of OFDM symbols and/or continuously changing absolute times) length).

The gNB 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in discrete and/or non-discrete configurations. In a discrete configuration, WTRUs 102a, 102b, 102c may communicate with gNB 180a, 180b, 180c without accessing other RANs (eg, such as eNodeB 160a, 160b, 160c). In a discrete configuration, the WTRUs 102a, 102b, 102c may use one or more of gNB 180a, 180b, 180c as a mobility anchor. In a discrete configuration, WTRUs 102a, 102b, 102c may use signals in unlicensed bands to communicate with gNB 180a, 180b, 180c. In a non-discrete configuration, WTRUs 102a, 102b, 102c may communicate/connect with gNB 180a, 180b, 180c, while also communicating/connecting with another RAN such as eNodeB 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-discrete configuration, eNodeB 160a, 160b, 160c may be used as a mobility anchor for WTRUs 102a, 102b, 102c, and gNB 180a, 180b, 180c may provide additional coverage for serving WTRUs 102a, 102b, 102C And/or liquidity.

Each of gNB 180a, 180b, 180c can be associated with a special cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and/or DL , Network cut support, dual connectivity, interworking between NR and E-UTRA, routing to user plane functions (UPF) 184a, 184b user plane data, routing to access and mobility management functions (AMF) Control plane information of 182a, 182b, etc. As shown in FIG. 1D, gNB 180a, 180b, and 180c can communicate with each other through the Xn interface.

The CN 115 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one conversation management function (SMF) 183a, 183b, and possibly data network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of CN 115, it should be understood that any of these elements may be owned and/or operated by an entity other than the CN operator.

The AMF 182a, 182b may be connected to one or more of the gNB 180a, 180b, 180c in the RAN 113 via the N2 interface, and may be used as a control node. For example, AMF 182a, 182b may be responsible for authenticating users of WTRUs 102a, 102b, 102c, supporting network cutting (eg, handling different PDU conversations with different needs), selecting special SMFs 183a, 183b, managing registration areas, NAS Termination of communication, action management, etc. AMFs 182a, 182b may use network cropping to customize CN support for WTRUs 102a, 102b, 102c based on the type of service of WTRUs 102a, 102b, 102c in use. For example, different network cuts can be established for different use cases, such as services that rely on ultra-reliable low latency (URLLC) access, services that rely on enhanced large-scale mobile broadband (eMBB) access, and/or Or services for machine type communication (MTC) access, etc. AMF 162 may provide for switching between RAN 113 and other RANs (not shown) that employ other radio technologies (eg, LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies, such as WiFi) Control plane function.

The SMF 183a, 183b can be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b can also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. SMF 183a, 183b can select and control UPF 184a, 184b, and configure the routing of traffic through UPF 184a, 184b. SMF 183a, 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU dialogue, controlling policy implementation and QoS, providing notification of downlink data, etc. The PDU conversation type can be IP-based, non-IP-based, Ethernet-based, and so on.

UPF 184a, 184b may be connected to one or more of gNB 180a, 180b, 180c in RAN 113 via the N3 interface, which may provide WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet Way 110 to facilitate communication between the WTRUs 102a, 102b, 102c and IP-enabled devices. UPF 184, 184b can perform other functions, such as routing and forwarding packets, implementing user plane policies, supporting multi-homed PDU conversations, handling user plane QoS, buffering downlink packets, providing mobility anchors, etc.

CN 115 can facilitate communication with other networks. For example, CN 115 may include an IP gateway (eg, an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 115 and PSTN 108, or may communicate with the gateway. In addition, CN 115 may provide WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In one embodiment, WTRUs 102a, 102b, 102c may be connected to local data via UPF 184a, 184b via the N3 interface to UPF 184a, 184b and the N6 interface between UPF 184a, 184b and DN 185a, 185b Network (DN) 185a, 185b.

In view of the corresponding descriptions of FIGS. 1A to 1D and FIGS. 1A to 1D, one or more or all of the functions described below with respect to one or more of the following may be provided by one or more simulation devices (not shown) Implementation: WTRU 102a-d, base station 114a-b, eNodeB 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and/or any one or more other devices described herein. These simulation devices may be one or more devices configured to simulate one or more or all functions described herein. For example, these simulated devices can be used to test other devices and/or simulated networks and/or WTRU functions.

These simulation devices may be designed to perform one or more tests of other devices in a laboratory environment and/or an operator network environment. For example, one or more simulation devices can perform one or more or all functions, and be fully or partially implemented and/or deployed as part of a wired and/or wireless communication network to test other devices in the communication network . One or more simulation devices can perform one or more or all functions, while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The simulation device may be directly coupled to another device to perform the test, and/or may use air wireless communication to perform the test.

One or more simulation devices may perform one or more (including all) functions, rather than being implemented/deployed as part of a wired and/or wireless communication network. For example, the simulation device may be used in test labs and/or non-deployment (eg, testing) test scenarios in wired and/or wireless communication networks in order to implement testing of one or more components. One or more simulation devices may be test devices. Direct RF coupling and/or wireless communication via RF circuits (eg, which may include one or more antennas) may be used by analog devices to transmit and/or receive data.

LTE authorized assisted access (LAA) and enhanced LAA (eLAA) can be implemented. Authorized Assisted Access (LAA) can be used as part of LTE Advanced Pro. The eLAA implementation can enable LTE uplink and downlink operations in unlicensed bands.

Can listen to wait for delivery (LBT).

The LBT agreement can be implemented in the LAA. The categories related to LBT may include one or more of the following: LBT without random backoff; LBT without random backoff; LBT with random backoff with fixed size contention windows; and LBT with random backoff with variable size contention windows.

For the case without LBT, the LBT-free program is executed by the transmitting entity.

For the case of LBT without random backoff, the duration of sensing that the channel is idle before transmission by the transmission entity may be determined.

For the case of a random back-off LBT with a fixed-size contention window, the LBT may include one or more of the following steps. The transmitting entity can randomly select N times in the contention window. The size of the contention window can be specified by the minimum and maximum values of N. The size of the contention window can be fixed. A random number N can be used in the LBT, for example to determine the duration that the transmission entity can sense the channel idle before transmitting on the channel.

For the case of a random back-off LBT with variable-size contention windows, the LBT may include one or more of the following. The transmitting entity can draw a random number N in the contention window. The size of the contention window can be specified by the minimum and maximum values of N. The transmission entity can change the size of the contention window, for example, when a random number N is drawn. The random number N can be used in LBT, for example, to determine the duration that the transmission entity can sense the channel idle before transmitting on the channel.

Interleaved resource allocation (eg, block (B)-IDMA) can be performed.

The resource allocation framework in the eLAA system can be implemented. For example, the basic unit of resource allocation for unauthorized data channels may be interleaved. Interleaving may include ten equally spaced resource blocks (RB) within a 20 MHz frequency bandwidth. For example, due to regulatory requirements in unlicensed frequency bands (eg, occupied bandwidth and 10dBm/MHz requirements), an interleaved structure in frequency can be used to allow the wireless transmit/receive unit (WTRU) to utilize the maximum available transmit power. Figure 2 shows an exemplary interlace. For example, as shown in Fig. 2, the interleaving may consist of 120 subcarriers of the OFDM symbol. The subcarriers may be distributed in a cluster manner, where the cluster size (for example, each cluster size) may be 12, and the clusters may be separated from each other by 9×12 subcarriers.

Interleaved resource allocation can (for example only) be applied to data channels. You can use licensed bands to transmit control channels (for example, PUCCH) and random access channels (RACH).

A random access channel i may be performed (eg, a physical random access channel as may be shown).

A WTRU attempting to access the network may transmit a random access preamble in a physical random access channel (PRACH) (for example, in NR).

Sequences can be generated.

等式1

等式2 從中可以根據等式3產生頻域表示

等式3 其中

或

，這取決於表1和表2給出的PRACH前導碼格式。序列號

可以從邏輯根序列索引獲得，並且

可以是循環移位。表 1

和

的 PRACH 前導碼格式

表 2

和

( 其中

) 的前導碼格式 格式

支援的受限集 A1 139

- A2 139

- A3 139

- B1 139

- B2 139

- B3 139

- B4 139

- C0 139

- C2 139

In NR, a random access preamble set can be generated according to equation (1) and equation (2)

Equation 1

Equation 2 From which the frequency domain representation can be generated according to Equation 3

Equation 3 where

or

, Which depends on the PRACH preamble format given in Table 1 and Table 2. serial number

Can be obtained from the logical root sequence index, and

It can be a cyclic shift. Table 1

with

The PRACH preamble format

Table 2

with

( Where

) Preamble format format

Supported restricted sets A1 139

- A2 139

- A3 139

- B1 139

- B2 139

- B3 139

- B4 139

- C0 139

- C2 139

等式4 其中

可以是振幅縮放因子，並且

可以是天線埠。可以產生OFDM信號。PRACH前導碼可以包括循環前綴、OFDM符號的重複和保護間隔。循環前綴、保護間隔、OFDM符號和重複次數的持續時間可以取決於例如PRACH前導碼格式。第3圖示出了PRACH前導碼結構的範例。The preamble sequence can be mapped to physical resources according to Equation 4

Equation 4 where

Can be an amplitude scaling factor, and

Can be an antenna port. OFDM signals can be generated. The PRACH preamble may include cyclic prefix, repetition of OFDM symbols, and guard interval. The duration of the cyclic prefix, guard interval, OFDM symbol, and number of repetitions may depend on, for example, the PRACH preamble format. Figure 3 shows an example of the PRACH preamble structure.

For example, when the resource allocation for PRACH is B-IDMA, the allocation of frequency resources may be discontinuous. Techniques for improving coverage relative to the coverage associated with continuous resource allocation and/or reducing the peak-to-average power ratio (PAPR) of the PRACH preamble may be provided here.

For example, when the physical uplink shared channel (PUSCH) and PRACH use different OFDM parameter configurations (eg, different subcarrier spacing), PUSCH and PRACH may interfere with each other due to interference from adjacent channels. Techniques to mitigate interference between PUSCH and PRACH can be provided.

If the LBT procedure fails (for example, due to LBT requirements), the WTRU may have to avoid access and transmission in the upcoming PRACH resources. This may increase the initial access delay in addition to the delays that, for example, gNB may schedule PRACH resources frequently and periodically (eg, due to unsuccessful LBT at gNB).

Block interleaved frequency division multiple access (B-IFDMA) can be used to perform PRACH sequence generation.

Zadoff-Chu sequences (for example, as in NR) can be used to generate PRACH preambles. The selected Zadoff-Chu sequence can be transmitted using the B-IFDMA method, for example. For example, a sequence (eg, Zadoff-Chu sequence) may be divided into L parts. L may correspond to the number of chunks in the interlace. A chunk includes (for example, is defined as) a continuous group of subcarriers. Interleaving may include L chunks. Some (eg, all) of the L chunks may not be adjacent in the frequency domain. In an example, chunks and resource blocks that include multiple consecutive subcarriers can be used interchangeably. The resource block may include (eg, defined as) 12 subcarriers. Portions of the sequence (eg, blocks) can be mapped to interleaved chunks (eg, resource blocks) allocated for random access preamble transmission. For example, each part of the sequence (eg, each block) may be mapped to an interleaved chunk allocated for random access preamble transmission (eg, one resource block).

Figure 4 shows an example of PRACH resource allocation with B-IDMA. As shown in FIG. 4, the sequence may be divided into L parts, and each of the L parts may be mapped to one resource block interleaved.

One resource block (for example, in NR) may have 12 subcarriers. The size of the interlace (for example, as shown in Figure 4) may be 12L subcarriers. For example, if L=12, the allocation size may be 144 subcarriers. If L=10, the allocation size may be 120 subcarriers. The allocation size may include, for example, the number of subcarriers allocated to the PRACH sequence.

The length of the sequence (eg, the number of subcarriers used for the sequence) may not be equal to the number of available subcarriers. For example, the length of the used sequence may be less than 120 (eg, 113), less than 144 (eg, 139), and so on. In order to map sequences to available resources (for example, subcarriers), one or more of the following may be used.

In an example, the sequence may be divided into multiple parts, so that the first L-1 part may have 12 elements (eg, coefficients), and the last part may have N-(12*(L-1)) coefficients, where N can be the sequence length. For example, if L=10 and N is 113, the last part may have 5 coefficients. M zeros may be mapped to resources of resource blocks that are not used by the sequence (eg, no sequence coefficients are mapped to those resources). In this example, the number of zeros mapped to the interleaved last resource block may be 12-5=7. As another example, if L=12 and N is 139, the last part may have 7 coefficients. The number of zeros mapped to the interleaved last resource block may be 12-7=5.

In an example, M zeros may be mapped to the last resource block of the interleaving or shared between the first resource block and the last resource block of the interleaving. M zeros may be mapped to the last M subcarriers of the last resource block interleaved. M zeros can be shared between the first k subcarriers of the first resource block interleaved and the last n subcarriers of the last resource block interleaved, where M=k+n. Figure 5 shows an example of PRACH sequence mapping. In Figure 5, assume N=113 and L=10. The first sequence portion that can be mapped to the first RB can have 8 coefficients, and the last sequence portion that can be mapped to the last RB can have 9 coefficients. The remaining sequence part may be mapped to the remaining 8 RBs, each of which is used to map the 12 coefficients of the sequence (eg, PRACH sequence).

。For example, before generating the OFDM signal from the PRACH sequence, the (eg, each) sequence portion of the PRACH sequence may be multiplied by the phase factor. The multiplication of the sequence part and the phase factor can reduce the PAPR of the OFDM signal generated from the PRACH sequence. The phase factors can be selected from a set (eg, a small set), and/or the sequence factors can be saved in a table for use in sequences (eg, each sequence). As an example, the phase factor can be selected from {1, -1, i, -i} or {1+i, 1-i, -1-i, -1+i}, where

.

Figure 6 shows an example of PRACH preamble OFDM signal generation. As shown in Figure 6, a discrete Fourier transform (DFT) block can be used to transform the PRACH sequence into the frequency domain. For some sequences, such as Zadoff-Chu sequences, DFT blocks can be skipped. The DFT spreading sequence may be divided into L parts, for example, part 1 to part L. The (for example, each) part may be multiplied by a phase factor, for example, phase factor 1 to phase factor L. The phase factor 1 to the phase factor L may be the same. Some (eg, all) phase factors 1-L may be different. Sequence parts (eg, each sequence part) may be mapped to one resource block interleaved. The OFDM signal can be generated by inverse discrete Fourier transform (IDFT). The phase factor of one or more sequences (eg, each sequence) can be calculated offline and/or saved in a table.

The examples herein can be similarly applied to other types of sequences, such as those derived from Zadoff-Chu sequences. The size of the chunk may be 12 subcarriers, or may not be 12 subcarriers. Chunks can include any number of subcarriers, for example, depending on the specific design.

When the subcarrier spacing of the PRACH preamble is different from the subcarrier spacing of the PUSCH, one or more examples described herein can be applied. Figure 7A shows three sample cases, where PRACH and PUSCH resource blocks have different parameter configurations (eg, subcarrier spacing, bandwidth, etc.). For example, when PRACH and PUSCH resource blocks have the same number of subcarriers, PRACH and PUSCH resource blocks may have different bandwidths, and the subcarrier spacings of PRACH and PUSCH are different. The size of the PUSCH RB can be used as a reference to determine the PRACH chunk size.

In FIG. 7A (a), the size of PUSCH RB may be 12×30 kHz=360 kHz, and the size of PRACH RB may be 12×15 kHz=180 kHz. PRACH RB (for example, each PRACH RB) may belong to different interlaces. For example, each RB can be used (eg, defined as) to interleave a "chunk".

In FIG. 7A (b), the size of PUSCH RB may be 12×15 kHz=180 kHz, and the size of PRACH RB may be 12×30 kHz=360 kHz. The PRACH RB may belong to an interlace. For example, the PRACH RB may be used (for example, defined as) a "chunk" of interlaces.

In Fig. 7A(c), the size of PUSCH RB may be 12×15 kHz=180 kHz, and the size of PRACH RB may be 12×1.25 kHz=15 kHz. Multiple PRACH RBs (for example, 12 PRACH RBs) may constitute an interleaved “chunk”.

Narrowband PRACH sequence generation can be performed. The PRACH preamble (eg, including PRACH sequence) or PRACH sequence may be generated in a portion of the channel. For example, as described herein, the PRACH sequence may be continuous or interlaced within the portion of the channel.

In an example, the PRACH sequence may be transmitted in at least a portion of the channel bandwidth (eg, cluster 720 as shown in Figure 7B). Fig. 7B shows an example of PRACH sequence mapping. Although one or more examples described herein can assume one part/cluster, one or more examples can be applied to more than one part/cluster. The PRACH sequence can be derived from a Zadoff-Chu sequence or another type of sequence (eg, Golay sequence).

As shown in (a) and (b) of FIG. 7B, some subcarriers in the frequency domain may be used for PRACH (for example, PRACH sequence). PRACH can be allocated subcarriers in the frequency domain. The PRACH sequence may be mapped to subcarriers (eg, allocated subcarriers), for example, to one or more subcarriers allocated to PRACH. The subcarriers used for the PRACH sequence may be continuous (for example, as shown in (a) in FIG. 7B) or interleaved (for example, as shown in (b) in FIG. 7B). The PRACH sequence may be processed (eg, pre-processed) before being mapped to the allocated subcarriers, for example. An example of pre-processing may be DFT transforming the sequence (eg, PRACH sequence).

One or more embodiments may be used to map PRACH sequences to resources (eg, subcarriers). The PRACH sequence may be mapped to a continuous set of subcarriers (for example, as shown in (a) of Figure 7B). The channel BW (eg, available channel BW) may be K ×Δf Hz, where K may be the number of subcarriers (eg, available subcarriers). Δf may be the subcarrier spacing (eg, for available subcarriers). For example, K may be 1024, and Δf may be 60 kHz, which results in a channel bandwidth of 61.440 MHz (eg, available channel bandwidth). The available channel bandwidth may include PRACH bandwidth. The bandwidth allocated to the PRACH sequence (for example, PRACH bandwidth) may be L × Δf Hz, for example, excluding any guard bands around subcarriers that can be inserted for the PRACH sequence. L may be the sequence length of the PRACH sequence. The sequence length may be the number of resources (eg, subcarriers) allocated and/or mapped to PRACH sequences. For example, the sequence length L may be 139 (for example, as shown by hatching in (a) of FIG. 7B), and Δf may be 60 kHz, which results in a PRACH bandwidth of 8.340 MHz.

Figure 7B shows one or more of the following. The PRACH sequence can be mapped to a set of interleaved subcarriers. As shown in (b) of FIG. 7B, the subcarriers used for the PRACH sequence may be interleaved between some subcarriers. The PRACH sequence can be mapped to some subcarriers, but not to other subcarriers. The PRACH sequence may be mapped to subcarriers 702-710. For example, the PRACH sequence may not be mapped to the three subcarriers 712, 714, and 716 between the subcarriers 702 and 704. Figure 7B shows an example of mapping to every fourth subcarrier, but other mappings can be used (for example, see the example in Table 3).

Δf may be the subcarrier spacing between two subcarriers (eg, two adjacent subcarriers, such as 702 and 712). As the subcarrier spacing Δf changes, the PRACH sequence can be mapped to different subcarriers. The number of subcarriers between two subcarriers used for the PRACH sequence (for example, subcarriers not used for the PRACH sequence) may be changed (for example, see Table 3). For example, the PRACH sequence may be mapped to certain subcarriers, so that if the subcarrier spacing Δf decreases, there may be more than three subcarriers that are not mapped to the PRACH sequence between the subcarriers 702 and 704. For example, the number of subcarriers between two subcarriers (for example, subcarriers 702 and 704) used in the PRACH sequence may vary in proportion to the upsampling rate of the PRACH format (for example, see Table 3). In an example, when the upsampling rate is 1, the number of subcarriers between two subcarriers (eg, subcarriers 702 and 704) used for the PRACH sequence may become zero. When the number of subcarriers between the subcarriers 702 and 704 becomes zero, the subcarriers used for the PRACH sequence may be continuous (for example, as shown in (a) of FIG. 7B).

The WTRU may receive information about the channel (eg, the channel the WTRU is trying to access). The information about the channel may include the subcarrier spacing of the channel. The information about the channel can indicate the increase or decrease of the subcarrier spacing of the channel.

In (b) of FIG. 7B, a subcarrier spacing smaller than that in (a) of FIG. 7B may be used. If the subcarrier spacing in (a) in Fig. 7B is Δf, the subcarrier spacing in (b) in Fig. 7B may be Δf/ m , where m is an integer. If m = 4 in (b) in Figure 7B, the subcarrier spacing may be 15 kHz (for example, 60 kHz/ m ). In the example, if the subcarrier spacing is Δf/ m , the total number of available subcarriers can become ( m × L ). For example, in (a) of FIG. 7B, the subcarrier spacing Δf may be 60 kHz, and K may be 1024, which results in an available channel bandwidth of 61.440 MHz. If the subcarrier spacing in (b) in Figure 7B is 15 kHz, a total of 4096 (eg, 1024× m ) subcarriers are available in the channel bandwidth of 61.440 MHz.

The total number of available subcarriers in the PRACH bandwidth can be increased from (a) in Figure 7B to (b) in Figure 7B. If the subcarrier spacing is Δf/ m , the total number of available subcarriers in the PRACH bandwidth can become m × L. For example, 556 ( m × 139) subcarriers can be used for PRACH sequence transmission within the PRACH bandwidth of 8.340 MHz. From (a) in Figure 7B to (b) in Figure 7B, the PRACH bandwidth may not change, for example, as shown in ( m × L ) × (Δf/ m ) = L × ΔfHz.

The PRACH sequence length can be fixed. For example, assume that the subcarrier spacing changes from (a) in Figure 7B to (b) in Figure 7B (for example, in (a) in Figure 7B and (b) in Figure 7B L), does not change the length of the PRACH sequence, the sequence may be mapped to the PRACH L subcarriers (e.g., see Table 3) PRACH bandwidth of m × L available subcarriers. Various techniques can be used to select L subcarriers from m × L available subcarriers.

The L sub-carriers used for PRACH sequence transmission can be selected to use every m- th sub-carrier within the PRACH bandwidth. For example, the PRACH sequence may be up-sampled at a rate of m , for example, before being mapped to subcarriers in the PRACH bandwidth, and the PRACH sequence length may be kept fixed by mapping. In an example, before the PRACH sequence is mapped to a subcarrier in the PRACH bandwidth, zeros may be inserted between the coefficients of the PRACH sequence.

The L subcarriers used for PRACH sequence transmission may be selected according to the availability of the channel or the availability of subcarriers in the channel. For example, if every m- th subcarrier is not available within the PRACH bandwidth, the PRACH sequence may not be mapped to every m- th subcarrier. The PRACH sequence can be mapped to some other subcarriers in the PRACH bandwidth to keep the sequence length fixed.

Subcarriers (eg, within PRACH bandwidth) can be indexed. Assuming that subcarriers within the PRACH bandwidth (for example, subcarriers (for example, (b) in Figure 7B (for example, 702, 712, 714, 716, and 704)) use indexes 0, 1, 2, ..., m × L -1 indicates that the index of the subcarrier to which the PRACH sequence is mapped (for example, the subcarriers of (b) in Figure 7B (for example, 702 and 704)) can be written as n × m , n=0,. .., L -1. As an example, if L = 16 and m = 4, the indexes of subcarriers that can be used for PRACH transmission (for example, mapped to PRACH sequences) may be the following set: {0,4,8,...,60}.

Fig. 7C shows an example of PRACH transmission. The PRACH transmission may be equivalent to up-sampling the PRACH sequence at a rate of m , and mapping the up-sampled PRACH sequence to IDFT, as shown in FIG. 7C. As shown in Figure 7C, the PRACH sequence can be preprocessed. For example, the preprocessing may include DFT transformation. Pre-processing may be optional. The PRACH sequence (eg, pre-processed PRACH sequence) may be upsampled (eg, based on m upsampling rate). The up-sampled PRACH sequence can be mapped to subcarriers (eg, by subcarrier mapping). Subcarrier mapping may include determining a subset of subcarriers from available subcarriers and mapping the PRACH sequence to the determined subset of subcarriers. The subcarrier index can be used for subcarrier mapping. For example, k may be the subcarrier index. Available sub-carriers may be indexed as k = {0 ... N ... N + m × L -1 ... m × K -1}. The up-sampled PRACH sequence can be mapped to subcarriers with index k = { N , N +1, ... N + m × L -1}. IDFT can be used to process the mapped subcarriers, for example, based on PRACH bandwidth. The output of the IDFT may be one or more signals with m repetitions (for example, in m subcarriers).

FIG. 7D shows a sampled time-domain signal (for example, the output of IDFT). Figure 7B (a) shows an example of a continuous PRACH sequence. Figure 7B (b) shows an example of interleaved PRACH sequences. For example, IDFT of size 16 can be used in Figure 7B (a). In Figure 7B (a), the PRACH sequence s=[1+1i -1-1i -1+1i 1-1i]/sqrt(2) can be mapped to the sub-indexes k = 0, 1, 2 and 3 Carrier wave. In this example, IDFT of size 64 can be used in Figure 7B (b). In Figure 7B (b), the PRACH sequence can be mapped to subcarriers with index k = 0, 4, 8, 12. The subcarrier spacing in Fig. 7B (b) may be Δf. The PRACH bandwidth can be 16Δf. If the PRACH bandwidth in Fig. 7B (a) includes 4 subcarriers in Fig. 7B (a) and m = 4, the PRACH bandwidth in Fig. 7B (b) may include 16 subcarriers.

The size of the IDFT output signal can be scaled appropriately (eg, proportionally) to the size of the IDFT. As shown in FIG. 7C, the signal at the output of the IDFT with a size of 64 can be repeated four times the signal at the output of the IDFT with a size of 16. The index k (eg, N in Figure 7C) of the first subcarrier within the system bandwidth (eg, PRACH bandwidth) to which the first coefficient of the PRACH sequence is mapped can satisfy the condition mod ( N , m ) = 0, for example to obtain (eg, maintain) a repetitive signal structure.

In this example, with proper scaling and subcarrier mapping, the first time domain signal generated based on (a) of FIG. 7B and the second time domain signal generated based on (b) of FIG. 7B may be the same. The time domain characteristics of the PRACH sequence in FIG. 7B (a) and FIG. 7B (b) may be the same.

The attributes of an implementation with a smaller subcarrier spacing (for example, the implementation in (b) of Figure 7B) may include at least one of the following: PRACH may be transmitted at the same subcarrier spacing as other channels (PUSCH); Multiplex more than one WTRU in the PRACH bandwidth; the WTRU can select the corresponding output of the IDFT to transmit all or part of the repetition.

PRACH may not require a wider subcarrier spacing, which may not be exclusive to PRACH. PUSCH can support narrower subcarrier spacing. For example, if the PUSCH supports a narrower subcarrier spacing, the PRACH can be transmitted with the same subcarrier spacing as the PUSCH. Using the same subcarrier spacing to transmit PRACH and PUSCH can reduce WTRU complexity.

More than one WTRU can be multiplexed in the PRACH bandwidth. For example, up to m WTRUs can be multiplexed within the same PRACH bandwidth. This can be implemented by, for example, introducing a cyclic shift after upsampling the block. The cyclic shift can be between 0 and m -1. In an example, subcarriers that may have indices { N + r , N + m + r , N + 2 m + r , ..., N + m ( L -1) + r } may be filled. r may be a shift value. mod( N + r , m ) may not be equal to 0. The signal may not have a repeating structure. The WTRU may be configured with an r value. The WTRU can receive r- valued messages. The WTRU may select the subcarrier to which the PRACH sequence is mapped. In an example, the first WTRU and the second WTRU may be multiplexed in the PRACH bandwidth. The first WTRU may use the PRACH format associated with the first PRACH sequence with the first cyclic shift, and the second WTRU may use the PRACH format associated with the second PRACH sequence with the second cyclic shift. The PRACH bandwidth may include at least one subcarrier mapped to the first PRACH sequence and at least one subcarrier mapped to the second PRACH sequence.

The WTRU may select the corresponding output of IDFT to transmit all or some repetitions, for example, after potentially inserting a cyclic prefix and/or guard interval.

The WTRU may determine the PRACH format to use (eg based on information about the channel). The specific PRACH format may be associated or/and determined based on one or more of the following: subcarrier spacing, upsampling rate, sequence length, or PRACH bandwidth. For example, the WTRU may use wider or narrower subcarrier spacing to generate the PRACH preamble. Table 3 provides a sample PRACH configuration table. The WTRU may be configured with one or more PRACH formats. As shown in Table 3, the sequence length can be designed to be fixed from one PRACH format to another PRACH format. One or more of the sub-sampling rate, sub-carrier spacing and/or PRACH bandwidth can be changed from one PRACH format to another PRACH format. As shown in PRACH format 1-3, the upsampling rate may vary based on (eg, proportional to the subcarrier spacing) subcarrier spacing, for example, to keep the sequence length fixed.

The PRACH format may be selected and/or used to control the WTRU's transmission power. For example, the WTRU may be configured with a PRACH format with a narrower PRACH bandwidth (eg, due to the power spectral density (PSD)/MHz rule). Narrower transmission bandwidth may result in lower transmission power. The WTRU can be close to the base station. For example, when an already connected WTRU is ready for handover, the WTRU may be configured with a PRACH format with a narrower PRACH bandwidth. The WTRU may be configured with a PRACH format with a narrower PRACH bandwidth and multiple PRACH OFDM symbol repetition, for example, to compensate for power loss due to narrow-band PRACH transmission.

In an example, the WTRU may (eg, initially) begin to try to access the channel by transmitting the PRACH preamble using the first PRACH format. The WTRU may determine whether the attempt to access the channel is successful based on the indication. The WTRU may receive the indication and information about the channel the WTRU received. If random access is unsuccessful (for example, determined by the WTRU based on the indication), the WTRU may change the first PRACH format, for example, so that the WTRU may transmit with greater power. For example, the WTRU may change the first PRACH format to a second PRACH format with a larger PRACH bandwidth and/or larger subcarrier spacing (eg, between PRACH formats listed in Table 3). As an example, the WTRU may use PRACH format 5 in its first attempt; if unsuccessful, the WTRU may try PRACH format 4 in its second attempt, and so on. In one example, the WTRU may use PRACH format 5 in its first attempt; if unsuccessful, the WTRU may try PRACH format 3 in its second attempt, and so on. Table 3 : Sample PRACH configuration table

LBT considerations can be used to implement LBT.

Narrowband PRACH can be used relative to channel access and/or LBT. The WTRU may try to access the narrowband PRACH. A WTRU attempting to access a narrow-band PRACH may perform LBT (eg, sub-band LBT) on a portion (eg, a subset) of the PRACH's bandwidth. When performing sub-band LBT, energy measurement may be performed across the bandwidth of the PRACH resource or across the minimum bandwidth (for example, whichever is narrower). The minimum bandwidth may be narrower than the PRACH resource bandwidth. The measured energy can be compared with the critical value. The critical value may be scaled according to the bandwidth of the subband, for example. For example, if the LBT critical value of a 20 MHz channel (eg, in the 5 GHz spectrum) is -72 dBm, the LBT critical value of the 2 MHz subband (eg, narrow-band PRACH is suitable) may be -62 dBm. The 2 MHz sub-band may be a suitable bandwidth for narrow-band PRACH.

The WTRU may (eg, in parallel) perform multiple sub-band LBT(s). At least one (eg, each) of the plurality of subbands LBT (one or more) may be associated with the scheduled PRACH resource. For example, gNB can schedule multiple narrow-band PRACH resources. Multiple narrow-band PRACH resources can be multiplexed in frequency. The sub-band LBT may be associated with narrow-band PRACH resources. The WTRU may execute multiple subband LBTs (one or more) (eg, parallel), and may successfully complete one or more subband LBTs (one or more). In an example, after successfully completing one or more sub-band LBT(s), the WTRU may access one or more scheduled PRACH resources associated with the successfully completed sub-band LBT(s) And/or transmit one or more preambles on one or more scheduled PRACH resources. WTRU behaviors that include the execution of multiple subband LBTs (one or more) can increase the chance of the WTRU successfully performing channel access. In an example, when multiple subband LBT(s) are performed in parallel, the WTRU may perform broadband energy measurements and/or may perform appropriate partitioning, for example, to obtain measured energy on individual subbands. The measured energy can be compared with the sub-band LBT threshold, for example, after broadband energy measurement and/or appropriate division to obtain the measured energy on individual sub-bands.

The LBT threshold used in the sub-band LBT(s) may be scaled, for example, according to the bandwidth of PRACH resources (eg, scheduled PRACH resources). In an example, gNB can schedule multiple PRACH resources that are multiplexed in frequency (eg, narrow-band PRACH resources). The narrowband PRACH resources (eg, each) may be associated with one or more pre-configured bandwidth sizes (eg, scheduling). The WTRU may perform multiple sub-band LBTs (eg, in parallel) by comparing the measured energy with an appropriate LBT threshold. The (eg, each) sub-band LBT(s) may be associated with scheduled PRACH resources (eg, narrow-band PRACH resources associated with one or more pre-configured bandwidth sizes). A suitable LBT threshold may be an LBT threshold, which is scaled, for example, according to the bandwidth of narrow-band PRACH resources (eg, one or more pre-configured bandwidth sizes). The WTRU may access the one or more associated PRACH resources and/or transmit the preamble on the one or more associated PRACH resources (eg, when one or more subband LBTs are successfully completed).

When the WTRU accesses more than one PRACH resource (eg, when LBT is successfully completed on each of the more than one PRACH resource), the WTRU may be configured to use the same PRACH sequence across some (eg, all) of the resources And/or use different PRACH sequences across some (eg, all) of multiple PRACH resources. Configurations that use the same PRACH sequence across some (eg, all) resources can enhance PRACH sequence detection, for example, on the gNB side. The use of different PRACH sequence configurations across multiple PRACH resources can reduce the chance of PRACH sequence collisions (eg, between WTRUs accessing the same PRACH resource).

If the WTRU is configured to use different PRACH sequences across multiple PRACH resources, the WTRU's behavior may include one or more of the following. The WTRU may receive multiple random access responses (RAR). (Eg, each) RAR may be associated with one of multiple (eg, transmitted) PRACH resources. For example, each RAR may correspond to one of multiple (eg, earlier transmitted) PRACH resources. If the WTRU receives multiple RARs, the WTRU may take one or more subsequent actions on one of the received multiple RARs. For example, the WTRU may not take subsequent actions with respect to other RARs among the received multiple RARs. In an example, the WTRU may take action on the RAR received first, and/or ignore the RAR received after (eg, next to) the RAR received first. RAR may be associated with the PRACH sequence transmitted earlier. The WTRU may take action on one or more earliest received RARs, which are scheduled for subsequent transmissions performed by the WTRU. The WTRU may take no action against other RARs received by the WTRU (eg, RARs scheduled for one or more subsequent transmissions). The WTRU may prepare to transmit the first scheduled (for example, in a previously received RAR) transmission allowed by the appropriate LBT procedure. In the event that LBT fails, the WTRU may prepare to transmit the second scheduled (eg, within the next RAR) transmission allowed by the appropriate LBT procedure and so on.

In an example, gNB may transmit multiple RAR responses, for example, in response to a PRACH transmission performed by the WTRU. RAR may include an indication that RAR is associated with PRACH transmission. (Eg, each) RAR response may provide scheduling resources for subsequent transmissions performed by the WTRU (eg, WTRU's response). The WTRU may (eg, follow the same behavior as described herein) take one or more actions on one of the received multiple RARs to, for example, the best resource, the first resource, or the successful LBT for the resource After the first resource is transmitted.

PUSCH puncturing can be performed.

For example, when PRACH uses B-IFDMA, the resource blocks for PRACH and PUSCH may be adjacent (for example, as shown in FIG. 7A). Resource blocks (eg, for PRACH and PUSCH) may be used by different WTRUs. When one or more configuration parameters (for example, one or more subcarrier spacing) of PRACH and PUSCH are different, for example, leakage from a PUSCH signal to a PRACH signal may occur. Applying filters to the transmission bandwidth (eg, the entire transmission bandwidth) may or may not reduce leakage, for example, due to the distributed allocation of RBs. Various techniques can be used to reduce leakage. For example, applying windowing to OFDM signals can reduce leakage. Filtering RBs (eg, each RB (eg, individually)) can reduce leakage. Some guard bands (one or more) between PRACH and PUSCHRB can be used (for example, as needed). In an example, the WTRU transmitting in the PUSCH RB may puncture one or more of the edge subcarriers of the PUSCH RB. The WTRU may rate match the WTRU's code blocks, for example, adjust the WTRU's transmission rate. One or more of the edge subcarriers of PUSCH RB may be nulled out. For example, one or more edge subcarriers of PUSCH RB may not be loaded with data symbols. Figure 8 shows an example of PUSCH puncturing. The subcarriers on one or both edges of the PUSCH RB may be punctured (for example, as needed). As shown in Figure 8, PRACH resources and PUSCH resources may be adjacent. The PRACH resource may include multiple PRACH subcarriers. The PUSCH resource may include multiple PUSCH subcarriers. PUSCH subcarriers 802 and 804 may be located on the edge of PUSCH resources. In the example shown in FIG. 8, PUSCH subcarriers 802 and 804 are punctured. The WTRU may be indicated (eg, signaled) the number and location (eg, identifier) of the punctured subcarriers (eg, each RB interleaved) in the RB. The indication may be based on at least one of: semi-static configuration; dynamic signaling; or implicit determination performed by the WTRU. In the example shown in FIG. 8, the number of punctured subcarriers may be 2. The number 2 and location of PUSCH subcarriers 802 and 804 may be indicated to the WTRU.

In an example, the WTRU may learn (eg, by indication) one or more time/frequency locations of PRACH resources (eg, PRACH RB in a cell). For example, when the WTRU is to transmit in the PUSCH, the WTRU may determine whether the PUSCH RB is adjacent to the PRACH RB. The WTRU may determine whether the frequency domain distance between the two types of RBs (for example, PRACH RB and PUSCH RB) is below a critical value. If the frequency domain distance between PRACH RB and PUSCH RB is lower than a critical value, the WTRU may determine that PRACH RB and PUSCH RB are adjacent. If the WTRU determines that the PRACH RB and PUSCH RB are adjacent, the WTRU may puncture certain subcarriers (eg, PUSCH subcarriers adjacent to the PRACH RB). The number of subcarriers to be punctured and/or one or more positions of the subcarriers to be punctured may be configured by the central controller, or may be fixed and determined by standards, for example. One or more positions of the subcarriers may include left edge, right edge, both left and right edges, and so on.

In an example, the central controller may instruct (eg, command) the WTRU to apply puncturing using, for example, a control channel. The central controller may, for example, use control channels to start and/or stop through the stop holes. The central controller may configure the number of subcarriers to be punctured and/or one or more positions of the subcarriers to be punctured (eg, left edge, right edge, both left and right edges, etc.).

In an example, all subcarriers in the chunk allocated to PRACH transmission may not be utilized. Some subcarriers can be reserved as guard subcarriers (eg, empty subcarriers). As an example, as shown in (a) of FIG. 7A, two PRACH RBs may form one PRACH chunk in interleaving. Such interleaved WTRUs allocated for PRACH preamble transmission can make one or more chunk edge subcarriers unused and can (eg, only) map sequence coefficients to one or more chunks Middle part. The number of unused sub-carriers and their positions (eg, left edge, right edge, both left and right edges, etc.) can be configured (eg, by a central controller).

In an example, the PRACH sequence may be mapped to a part of subcarriers in the PRACH chunk (eg, only a part of subcarriers). The remaining subcarriers can be left blank. For example, the middle subcarriers of the chunk can be used to transmit the sequence, while the edge subcarriers can be empty. The length of the PRACH sequence can be selected so that it is equal to the number of subcarriers used. As an example, as shown in (a) of FIG. 7A, two PRACH RBs may form two different PRACH chunks in two PRACH interlaces. If an interlace has 120 sub-carriers (eg, 10 chunks times 12 sub-carriers), the length of the sequence may be selected as 59 (eg, instead of 113). In this case, 6 samples (eg, elements) of the sequence (eg, the first six samples) may be mapped to the middle subcarriers of the first group of blocks. Six samples (eg, samples 7-12) may be mapped to the middle subcarriers of the second group of blocks. Six samples (eg, samples 13-18) may be mapped to the middle subcarrier of the third group of blocks, and so on. Chunks (eg, the last chunk) can be used to transmit samples (eg, samples 55 to 59) in its middle subcarrier.

The Golay sequence can be used to perform PRACH sequence generation.

, n=1,…,N可以映射到第

個組塊，而

, n=1,…,N可以映射到第

個組塊。對於a =[1 1 1 -1i 1i]；b =[1 1i -1 1 -1i]；c =[1 1 1 1 -1 -1 -1i 1i 1 -1 -1i 1i]；d =[1 1 -1i -1i 1 1 -1i 1i 1i -1i 1i -1i]，其中

，第9圖中示出了樣本PRACH OFDM信號產生。如第9圖所示，c可以乘以a1-5，並且乘法結果可以映射到不同的RB（例如，如第9圖所示）。d可以乘以b1-5，並且乘法結果可以映射到不同的RB（例如，如第9圖所示）。The Golay sequence can be used as the PRACH sequence, and the PAPR of the Golay sequence can be limited to 3dB. Golay sequences can be generated from Golay's concatenation structure. For example, (a, b) and (c, d) can be complementary Golay sequences of length N and M, respectively. A Golay sequence with 2N non-zero parts can be generated, and/or parts (eg, each part) can be mapped to one or more (eg, one) chunks that are interleaved, for example, using B-IDMA resource allocation. E.g,

, n=1,…,N can be mapped to the first

Chunks, and

, n=1,…,N can be mapped to the first

Chunks. For a =[1 1 1 -1i 1i]; b =[1 1i -1 1 -1i]; c =[1 1 1 1 -1 -1 -1i 1i 1 -1 -1i 1i]; d =[1 1 -1i -1i 1 1 -1i 1i 1i -1i 1i -1i], where

Figure 9 shows sample PRACH OFDM signal generation. As shown in Figure 9, c can be multiplied by a1-5, and the multiplication result can be mapped to different RBs (for example, as shown in Figure 9). d can be multiplied by b1-5, and the multiplication result can be mapped to different RBs (for example, as shown in Figure 9).

The length of the Golay sequence may depend on certain factors. It may not be possible to generate Golay sequences of arbitrary length. The length of the Golay sequence may depend on the number of subcarriers allocated for PRACH transmission. For example, if the PRACH interlace includes 10 RBs of 12 subcarriers, a Golay sequence of length 120 may be generated (eg, as described herein). As another example, if the PRACH interlace includes 12 RBs of 12 subcarriers, a Golay sequence with a length of 144 (eg, as described herein, by using ( a , b ) with a length of 6 (eg, N =6)).

In some cases, it may be beneficial to have a longer PRACH sequence. For example, a long PRACH sequence (eg, in NR) may have 839 coefficients and/or use 1.25 or 5 kHz as the subcarrier spacing.

For example, 10 blocks may be used, where the bandwidth of the chunks (eg, each chunk) is 180 kHz. (For example, each) block may have 144 PRACH subcarriers, for example, for 1.25 kHz subcarrier spacing. For example, if subcarriers are used (eg, all subcarriers), a sequence with 1440 elements can be transmitted. For example, if chunks are used in part, shorter sequences can be transmitted. As an example, 96 subcarriers in 10 blocks (eg, each block) may be utilized, which results in a sequence of 960 elements (eg, the length of the sequence is 960). One of the construction implementations can be used, for example, to generate a sequence of 960 elements. For example, in one example, the signal shown in Figure 9 can be used, where ( c , d ) is a sequence of length 96.

等式5， 其中

可表示

和

的串連（concatenation）。

可意味著共軛和反轉y元素的順序。

和

可以是Golay互補序列對。給定一對長度N的序列

和

，等式5可以示出如何產生長度2N的序列對。該對的第一序列可以是

，及該對的第二序列可以是

。作為範例，如果

和

是長度為12的序列，則使用該遞迴三次（例如，如等式6中所示）可以產生長度為96的序列c 和d ：

等式4

等式4

等式6A sequence of length 96 can be generated recursively, for example, using Equation 5.

Equation 5, where

Representable

with

Concatenation (concatenation).

It can mean conjugating and reversing the order of y elements.

with

It can be a Golay complementary sequence pair. Given a pair of sequences of length N

with

, Equation 5 can show how to generate sequence pairs of length 2N. The first sequence of the pair can be

, And the second sequence of the pair can be

. As an example, if

with

Is a sequence of length 12, then using this recursion three times (for example, as shown in Equation 6) can produce sequences c and d of length 96:

Equation 4

Equation 4

Equation 6

For example, if x = [1 1 1 1 -1 -1 -1 1 1i -1i -1 1] and y = [1 1 1i 1i 1 1 -1 1 1 -1 1 -1], then the recursive construction can The following sequence is produced: c = [1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000 i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000 -1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000-1.0000 i 0.0000-1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.000 0 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.00000 0.0000 + 1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000 + 1.0000 i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000 -1.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i], d = [1.0000 + 0.0000i 1.0000 + 0.0000 i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0. 0000i 0.0000 + 1.0000i 0.0000 + 1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000 i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000-1.0000i 0.0000-1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000 i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i- 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000-1.0000i 0.0000-1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 0.0000-1.0000i 0.0000-1.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i 0.0000 + 1.0000i 0.0000-1.0000i 1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i -1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000i 1.0000 + 0.0000 i 1.0000 + 0.0000i].

Various Golay constructs can be used to implement offline design PRACH sequences. The length of the PRACH sequence may be fixed. The central controller may configure the WTRU with parameters that include one or more of the basic Golay sequence (eg, a , b , c, and d ), Golay construction implementation, and/or other parameters. The WTRU may build a sequence of a certain (eg, required) length offline based on parameters, for example. Sequences can be constructed and/or specified in the standard.

A total backoff counter assisted preamble transmission can be performed.

For example, in unlicensed spectrum, the transmission of the preamble may be subject to LBT. The availability of RACH time resources (eg, OFDM symbols to be used for preamble transmission (PT)) may depend on channel conditions. A preamble transmission window (PTW) can be used (eg, defined). Defining PTW can improve the probability of random access transmission. Fig. 10 shows an example of LBT in PRACH preamble transmission. The PTW (for example, the RACH window between time t0 and time t3, as shown in Figure 10) may include the time interval during which the WTRU may transmit the preamble. The PTW can be predefined or configured via the network, for example.

As shown in Figure 10, the WTRU may start the LBT procedure when the PTW is started, for example, at time t0. For example, at time t1, the WTRU may start transmitting the preamble. When the channel is available, the time t1 can be selected. The time t1 can be selected so that the OFDM symbols are aligned in time. For example, the time for transmitting the preamble may be aligned with the OFDM symbol in the time slot. For example, if the channel becomes available before time t1, the WTRU may transmit a reservation signal to occupy the channel. The preamble transmission can end at time t2. Time t2 may be less than or equal to time t3. If it is determined (eg, estimated/calculated) that time t2 is greater than time t3, the WTRU may not start preamble transmission. For example, if the preamble transmission exceeds the maximum PTW size due to the duration of the preamble (eg, before the WTRU can complete the preamble transmission), the WTRU may not start the preamble transmission.

Different WTRUs may determine (eg, find) channel availability at different times, for example, due to LBT operation. Figure 11 shows an example of multiple WTRUs performing LBT and PRACH preamble transmission(s) in PTW. In Figure 11, RACH WTRU1 and RACH WTRU2 transmit PT in the RACH window between time t0 and time t3. As shown in Figure 11 (a), RACH WTRU1 can perform LBT-1. RACH WTRU1 may start PT at time t1 after RACH WTRU1 performs LBT-1, and end PT at time t2. RACH WTRU2 can perform LBT-2. RACH WTRU2 may start the PT at time t4 after RACH WTRU2 performs LBT-2, and end the PT at time t5. As shown in Figure 11 (a), LBT-1 and LBT-2 are different. The PT of RACH WTRU1 and the PT of RACH WTRU2 do not completely overlap. For example, if PRACH preamble transmissions from different WTRUs do not (eg, completely) overlap, the detection performance at the receiver may degrade and/or deteriorate.

Different WTRUs may be configured to use a common backoff counter. For example, by using a common backoff counter, different WTRUs configured with the same PTW can align LBT. For example, as shown in FIG. 11(b), the WTRU may (eg, all) complete LBT simultaneously. Some or all WTRUs may find available channels and/or may, for example, start preamble transmission simultaneously, as shown in Figure 11 (b). By using a common backoff counter, for example, if the channel is not available when the WTRU's counter expires, the WTRU may wait for the next PTW opportunity.

Different implementations can be used to configure the common backoff counter. Multiple WTRUs may be divided into subgroups. Subgroups of WTRUs (eg, each subgroup) may be configured with a common backoff counter. WTRU group specific information may be delivered to WTRU subgroups. The WTRU group specific information may include the configuration of the common backoff counter. The WTRU subgroup may receive the same information about the common backoff counter (eg, for PT). A common backoff counter may allow WTRUs in the same subgroup to align with each other for PTs.

The backoff counter may be used to align the WTRU's PTs within the same beam or across different beams. For example, a beam-specific backoff counter can be used in a beam-centric system. The common backoff counter can be used for WTRUs in the same beam, for example, because WTRUs residing in the same beam can receive the same information. Different backoff counters or common backoff counters may be used for WTRUs in different beams. Based on that WTRUs in different beams may receive different information and/or may not interfere with each other (eg, for PT), different backoff counters may be used for WTRUs in different beams. For example, when different beams interfere (eg, have mutual interference), a common backoff counter may be used to align WTRUs in different beams. WTRUs in different beams can receive a common backoff counter (eg, by different information transmitted from the network). The network may dynamically control individual beams or a group of beams (eg, all beams), which may be used to transmit a common backoff counter to the WTRU. When (for example, once) the WTRU receives information for the common backoff counter, the WTRU may use the information for the common backoff counter to align one or more of the same beam, span some different beams, or all different beams Preamble transmission.

Although the features and elements of the device and/or technology are described in particular combinations, one or more, or each feature and/or element may be used alone without other features and/or elements, or with or without other features And/or elements in various combinations.

Although one or more techniques described herein consider LTE, LTE-A, NR, and/or 5G specific agreements, it should be understood that the techniques described herein are not limited to this scenario and are also applicable to other wireless systems.

The above procedure may be implemented in a computer program, software, and/or firmware incorporated in a computer-readable medium to be executed by the computer and/or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and/or wireless connections) and/or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media, such as but not limited to internal hard drives Discs and removable disks, magneto-optical media and/or optical media, such as CD-ROM discs, and/or digital versatile discs (DVD). The processor associated with the software may be used to implement radio frequency transceivers for use in WTRUs, terminals, base stations, RNCs, and/or any host computer.

100‧‧‧Communication system 102, 102a, 102b, 102c, 102d ‧‧‧ Wireless Transmission/Reception Unit (WTRU) 104, 113‧‧‧ Radio Access Network (RAN) 106、115‧‧‧Core network (CN) 108‧‧‧ Public Switched Telephone Network (PSTN) 110‧‧‧Internet 112‧‧‧Other network 114a, 114b ‧‧‧ base station 116‧‧‧Air interface 118‧‧‧ processor 120‧‧‧Transceiver 122‧‧‧Transmission/Reception 124‧‧‧speaker/microphone 126‧‧‧Keyboard 128‧‧‧Display/Touchpad 130‧‧‧non-removable memory 132‧‧‧ removable memory 134‧‧‧Power 136‧‧‧Global Positioning System (GPS) chipset 138‧‧‧Peripheral equipment 160a, 160b, 160c‧‧‧e Node B (eNB) 162‧‧‧Mobile Management Gateway (MME) 164‧‧‧ Service Gateway (SGW) 166‧‧‧Packet Data Network (PDN) Gateway (or PGW) 180a, 180b, 180c, 202, 304, 404, 704‧‧‧ gNB 182a, 182b‧‧‧Access and mobility management function (AMF) 183a, 183b‧‧‧ Dialogue management function (SMF) 184a, 184b ‧‧‧ user plane function (UPF) 185a, 185b ‧‧‧ data network (DN) LBT‧‧‧Listen first IDFT‧‧‧Inverse Discrete Fourier Transform PRACH‧‧‧Physical Random Access Channel PT‧‧‧Preamble transmission PUSCH‧‧‧Physical on-chain shared channel RACH‧‧‧Random access channel RB‧‧‧Resource block t0, t1, t2, t3, t4, t5‧‧‧‧ WTRU‧‧‧Wireless Transmission/Reception Unit

In addition, the same reference numerals in the drawings denote the same elements, and in which: FIG. 1A is a system diagram illustrating an example communication system that can implement one or more disclosed embodiments; FIG. 1B is a system diagram showing an exemplary wireless transmission/reception unit (WTRU) that can be used in the communication system illustrated in FIG. 1A according to an embodiment; FIG. 1C is a system diagram showing an exemplary radio access network (RAN) and an exemplary core network (CN) that can be used in the communication system shown in FIG. 1A according to an embodiment; FIG. 1D is a system diagram showing another exemplary RAN and another exemplary CN that can be used in the communication system shown in FIG. 1A according to an embodiment; Figure 2 shows an example of interleaving. Figure 3 shows an example of the PRACH preamble structure. Figure 4 shows an example of PRACH resource allocation with block interleaved multiple access (B-IDMA). Figure 5 shows an example of PRACH sequence mapping. Figure 6 shows an example of PRACH preamble orthogonal frequency division multiplexing (OFDM) signal generation. Figure 7A shows an example of different parameter configurations for PRACH and physical on-chain shared channel (PUSCH). Fig. 7B shows an example of PRACH sequence mapping. Fig. 7C shows an example of PRACH transmission. FIG. 7D shows an example of PRACH time-domain signals. Figure 8 shows an example of perforated PUSCH. Figure 9 shows an example of PRACH OFDM signal generation using Golay sequences. Fig. 10 shows an example of LBT in PRACH preamble transmission. Figure 11 shows an example of LBT used in PRACH preamble transmission for multiple WTRUs.

PRACH‧‧‧Physical Random Access Channel

Claims (14)

A wireless transmission/reception unit (WTRU), including: A processor, the processor is configured as: Determining information related to the physical random access channel, where the information includes a subcarrier spacing associated with the physical random access channel; Determine a format associated with the physical random access channel, where the format includes at least one of an upsampling rate or a sequence length, where the sequence length is fixed, and the upsampling rate is based on randomness with the entity The information associated with the access channel varies, where the processor is configured to: If the physical random access channel has a first subcarrier spacing, the first upsampling rate is used, and If the physical random access channel has a second subcarrier spacing, use a second upsampling rate that keeps the sequence length at a fixed value; and Random access is performed using the determined format associated with the physical random access channel. The WTRU as described in item 1 of the patent scope, wherein the up-sampling rate indicates a sequence of a subcarrier group associated with the physical random access channel, and the subcarrier group is randomly accessed with the entity Within a bandwidth associated with the channel. The WTRU as described in item 1 of the patent scope, wherein the first subcarrier spacing is greater than the second subcarrier spacing, and the first upsampling rate is less than the second upsampling rate. The WTRU as described in item 1 of the patent application scope, wherein the processor is further configured to: Based on an indication received in the information about the channel, it is determined whether a first attempt to access the channel is successful, wherein the first attempt is based on including an upsampling rate associated with the first attempt A first format of For a second attempt, based on a determination that the first attempt was unsuccessful, determine a second format that includes an up-sampling rate associated with the second attempt, where the associated with the first attempt The upsampling rate is different from the upsampling rate associated with the second attempt; and Random access is performed using the determined second format associated with the physical random access channel. The WTRU as described in item 1 of the patent scope, wherein if the upsampling rate is 1, the subcarrier group includes consecutive subcarriers in the bandwidth associated with the physical random access channel, and if the If the sampling rate is 2, the subcarrier group includes the substitute subcarriers in the bandwidth associated with the physical random access channel. The WTRU as described in item 1 of the patent scope, wherein the determined PRACH format includes a subcarrier spacing that is to be transmitted by the WTRU for a physical uplink shared channel (PUSCH) spacing the same. The WTRU as described in item 1 of the patent scope, wherein the processor is configured to use the determined PRACH format to determine an output of an inverse discrete Fourier transform (IDFT) to transmit the PRACH preamble. A method performed by a wireless transmission/reception unit (WTRU) includes: Determining information related to a physical random access channel, where the information includes a subcarrier spacing associated with the physical random access channel; Determine a format associated with the physical random access channel, where the format includes at least one of an upsampling rate or a sequence length, where the sequence length is fixed, and the upsampling rate is based on randomness with the entity The information associated with the access channel varies, where: If the physical random access channel has a first subcarrier spacing, a first upsampling rate is used, and If the physical random access channel has a second subcarrier spacing, use a second upsampling rate that keeps the sequence length at a fixed value; and Random access is performed using the determined format associated with the physical random access channel. The method as described in item 8 of the patent application range, wherein the upsampling rate indicates a sequence of a subcarrier group associated with the physical random access channel, and the subcarrier group is randomly accessed with the entity Within a bandwidth associated with the channel. The method according to item 8 of the patent application scope, wherein the first subcarrier spacing is greater than the second subcarrier spacing, and the first upsampling rate is less than the second upsampling rate. The method as described in item 8 of the patent application scope also includes: Based on an indication received in the information about the channel, it is determined whether the first attempt to access the channel was successful, where the first attempt is based on including an upsampling rate associated with the first attempt A first format; For a second attempt, based on a determination that the first attempt was unsuccessful, determine a second format that includes an up-sampling rate associated with the second attempt, where the associated with the first attempt The upsampling rate is different from the upsampling rate associated with the second attempt; and Random access is performed using the determined second format associated with the physical random access channel. The method as described in item 8 of the patent application range, wherein if the upsampling rate is 1, the subcarrier group includes consecutive subcarriers in the bandwidth associated with the physical random access channel, and if the If the sampling rate is 2, the subcarrier group includes the substitute subcarriers in the bandwidth associated with the physical random access channel. The method of item 8 of the patent application scope, wherein the determined PRACH format includes a subcarrier spacing that is to be transmitted by the WTRU for a physical uplink shared channel (PUSCH) spacing the same. The method as described in item 8 of the patent application scope further includes using the determined PRACH format to determine an output of an inverse discrete Fourier transform (IDFT) to transmit a PRACH-preamble.

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